Fixed errors in BaseTool and doc; made CreateBaseMapTool 'extends' output more standard

I have added support for `--output-level` command option in my fork of PommBundle, but it depends on this fix here to work.

BaseTool was calling unexisting `$this->options->get(...)`. I changed it to `$this->options->getParameter(...)`.

How should I proceed with the Pull Request for PommBundle? People not using this commit of Pomm would receive an error. See akp999/PommBundle@cbec4e974ac0ae2db1a58103fe9d4caa0c254b84